powerpc/85xx: Add support for booting from NAND on MPC8572DS

Mimic support that exists on MPC8536DS on the MPC8572DS to allow booting
from NAND.

Signed-off-by: Jin Qing <b24347@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
6 files changed